Originally Posted By: wemay
Originally Posted By: Quattro Pete
530i MFR spec: LL-01, a number of viscosity grades can be used
C300 MFR spec: MB 229.5, a number of viscosity grades can be used
See sig for what I use.
Why? These are the cheapest oils I can find that still meet the mfg spec.
I would guess that for most Euro brands the specs are more important than Viscosity, correct?
Yes, that is probably true. If you're in spec, you will PROBABLY have an appropriate viscosity too. However, there are some particular engines, like certain AMGs, that want 229.5 plus a 40 weight, so not all of 229.5 options are available on those.
I think all of my cars allow for some variance in viscosity if other requirements are met. If that wasn't the case, I still wouldn't see the need to go outside of what the manufacturer allows/suggests.